One-component curable electrical insulation coating

Abstract

A one-component curable insulating coating composition comprises encapsulated catalysts and encapsulated curing agents mixed with an unsaturated resin. The encapsulated catalyst and/or curing agent is prevented from chemically contacting the resin until a cure temperature is achieved. The one-component coating composition has a shelf life that is equal to or greater than 6 months and a cure temperature and/or cure time that is lower than the cure temperature and/or cure time normally associated with currently available multi-component coating compositions.

1 . A curable insulating coating composition comprising an unsaturated polyester resin, epoxy or polyol and an encapsulated activator; said activator being chosen from the group consisting of an encapsulated curing agent, an encapsulated catalyst and combinations thereof, wherein said resin and encapsulated activator are mixed together to form a one component system in which said encapsulated activator is prevented from reacting with said resin until the composition is exposed to a desired cure temperature. 
     
     
         2 . The curable coating composition of  claim 1  wherein the curing agent is a peroxide and/or a metallic promoter. 
     
     
         3 . The curable coating composition of  claim 2  wherein the peroxide is selected from the group consisting of cumene hydroperoxide, tert-butyl perbenzoate, dicumyl peroxide, peroxides used in free radical reactions, and combinations thereof. 
     
     
         4 . The curable coating composition of  claim 2  wherein the metallic promoter is a metal salt. 
     
     
         5 . The curable coating of  claim 4  wherein the metal salt is chosen from the salts of cobalt, manganese, calcium, copper, zirconium, aluminum, tin, mercury, and combinations thereof. 
     
     
         6 . The curable coating composition of  claim 1  wherein the catalyst is chosen from the group consisting of Lewis acid catalysts, anhydrides, isocyanates, peroxides and combinations thereof. 
     
     
         7 . The curable coating composition of  claim 6  wherein the Lewis acid catalyst is chosen from the group consisting of such boron trifluoride, trichloride complexes and combinations thereof. 
     
     
         8 . The curable coating composition of  claim 6  wherein the anhydride is chosen from the group consisting of such as dodecenylsuccinic anhydride, methyltetrahydrophthalic anhydride, nadic methyl anhydride, and combinations thereof. 
     
     
         9 . The curable coating composition of  claim 6  wherein the isocyanate is chosen from the group consisting of methyldiphenyl isocyanates (MDI), toluene diisocyanate (TDI) and its polymers, aliphatic isocyanates, and combinations thereof. 
     
     
         10 . The curable insulating coating of  claim 1  wherein said coating composition has a shelf life equal to or greater than about 6 months. 
     
     
         11 . The curable insulating coating composition of  claim 1  wherein said coating composition has a sunshine gel temperature at 100° C. of about 5 to about 8 minutes. 
     
     
         12 . The curable insulating coating composition of  claim 1  wherein said coating composition has a helical coil bond strength of about 24 lbs to about 50 lbs. 
     
     
         13 . The curable insulating coating composition of  claim 1  wherein said coating composition has a glass transition temperature of about 145° C. 
     
     
         14 . The curable insulating coating composition of  claim 1  wherein said coating composition comprises about 100 pbw resin combined with about 1 to about 7 pbw encapsulated peroxide. 
     
     
         15 . A method of producing a one-component curable insulating coating composition comprising providing an encapsulated activator and mixing the encapsulated activator with a curable resin to form a substantially homogeneous mixture; said encapsulated activator being chosen from the group consisting of an encapsulated curing agent, an encapsulated catalyst, and combinations thereof. 
     
     
         16 . The method of  claim 15  wherein the resin is an unsaturated polyester resin. 
     
     
         17 . The method of  claim 15  wherein the curing agent is a peroxide and/or a metallic promoter. 
     
     
         18 . The method of  claim 17  wherein the peroxide is selected from the group consisting of cumene hydroperoxide, tert-butyl perbenzoate, dicumyl peroxide, peroxides used in free radical reactions and combinations thereof. 
     
     
         19 . The method of  claim 17  wherein the metallic promoter is a metal salt. 
     
     
         20 . The method of  claim 19  wherein the metal salt is chosen from the salts of cobalt, manganese, calcium, copper, zirconium, aluminum, tin, mercury, and combinations thereof. 
     
     
         21 . The method of  claim 15  wherein the catalyst is chosen from the group consisting of Lewis acid catalysts, anhydrides, isocyanates. 
     
     
         22 . The method of  claim 21  wherein the Lewis acid catalyst is chosen from the group consisting of such boron trifluoride, trichloride complexes and combinations thereof. 
     
     
         23 . The method of  claim 21  where the resin is an epoxy or a polyol. 
     
     
         24 . The method of  claim 21  wherein the anhydride is chosen from the group consisting of such as dodecenylsuccinic anhydride, methyl-tetrahydrophthalic anhydride, nadic methyl anhydride, and combinations thereof. 
     
     
         25 . The method of  claim 21  wherein the isocyanate is chosen from the group consisting of methyldiphenyl isocyanates (MDI), toluene diisocyanate (TDI) and its polymers, aliphatic isocyanates, and combinations thereof. 
     
     
         26 . A method of producing a one-component curable insulating coating composition consisting of mixing encapsulated peroxide with an unsaturated polyester resin. 
     
     
         27 . The method of  claim 26  wherein said mixing step comprises mixing together about 100 pbw resin, about 1 to about 7 pbw encapsulated peroxide. 
     
     
         28 . A curable insulating coating composition consisting of an unsaturated polyester resin and an encapsulated activator; said activator being chosen from the group consisting of an encapsulated curing agent, an encapsulated catalyst and combinations thereof, wherein said resin and encapsulated activator are mixed together to form a substantially homogeneous mixture in which said encapsulated activator is generally prevented from reacting with said resin until the composition is exposed to a desired cure temperature.